The type of small truck cushion hitch disclosed in the above patents has remained popular with purchasers and owners of small trucks, primarily pick-up trucks. The primary feature of this type of hitch is that the drawbar may be released from its locked position, and slid rearwardly and moved laterally to align the hitch member of the truck with the hitch member on the tongue of a trailer. After the hitch members are connected and the releases returned to their locked positions, the truck may be moved rearwardly and then forwardly to lock the drawbar of the hitch. During road travel, the drawbar member is spring-cushioned in the locked position, thereby providing a smoother ride and less load variation (i.e., shock load) on the transmission of the truck.
For the first few decades of its usage, the type of extendable cushion hitch with which the present invention is concerned was mounted to the truck frame using side brackets in a position immediately below the frame of the truck. In this case, the truck bumper was removed, and a replacement bumper, typically of universal application, was supplied as an integral unit with the hitch assembly.
With the proliferation of different sizes and styles of pick-up trucks, and the increasing number of domestic and foreign manufacturers of pick-up trucks for the U.S. market, and with the increasing sophistication of manufacturing techniques for increasing the strength of light truck vehicles, the frame configurations for light trucks have increased substantially. To have a uniquely designed cushion bumper hitch and mounting for each model of truck for every truck manufacturer would be prohibitive, particularly when it is realized that these types of products are not distributed directly from the manufacturer, but rather, they are distributed through dealers. Each dealer would have to stock an inordinately large number of hitch assemblies, each dedicated to one or a few truck models.
Moreover, manufacturers of small trucks, in an effort to increase their marketability to a larger number of customers, have adopted automotive styling features for the trucks. One such feature is the use of a rear bumper which is styled to match the truck and to curve around the rear corners. Further, bumpers of many such trucks are painted to match the color of the truck, as with passenger automobiles.
These automotive developments have created a number of problems for light truck owners desiring a heavy duty spring cushion bumper hitch. The first is that the bumper formerly sold with extendable cushion hitches does not match the color of the truck, and it is not styled in a rounded automotive design. Current purchasers of light trucks do not want to have their styled rear bumpers removed and replaced by a bumper which does not match the design and color of the truck they purchase.
If it is desired to place the bumper hitch beneath the original bumper of the truck, another mounting problem arises--namely, that by suspending the hitch assembly at a greater distance beneath the truck frame, greater forces are generated in the brackets which attach the hitch assembly frames to the truck frame since the hitch assembly is suspended beneath the frame at a greater distance than with bumper hitches which replace the rear bumper. This greater distance creates greater bending forces under load conditions on the brackets which attach the cushion bumper assembly to the vehicle frame.